INTERNATIONAL MARITIME ORGANIZATION

4 ALBERT EMBANKMENT, LONDON SE1 7SR

Telephone: 01-735 7611 Telegrams: INTERMAR-LONDON SE1 T , 'X'. 23588

Ref. T3/ 2. 03

IMO

CONTAINERS AND CARGOES

CARRIAGE OF GRAIN

MSC/Circ.488 6 June 1988

Guidance on interpretations and equivalences

Foreword

Experience with the application of chapter VI of SOLAS 1974 over a period

of twelve years has indicated that it would be beneficial to clarify, expand

upon, or otherwise explain certain regulations and sections thereof, in order

to insure uniform implementation on all ships subject thereto. The following

guidelines have been prepared to accomplish this purpose. They are not

intended as new or additional regulations but, instead, are furnished for

the guidance of approval agencies, port authorities, surveyors, and others

responsible for the utilization of chapter VI.

Introduction

The organization and format of the guidelines are based upon the

following precepts:

1 A guideline is not provided for each and every regulation and section.

2 The guidelines, when provided, are listed in the same order as the

pertinent regulations or sections as set forth in chapter VI, and are

serially numbered for identification.

3 Each guideline is further identified by a title appropriate to its

specific subject and not by the title of the regulation or section to

which it applies. However, the latter designation is always included as

a reference.

4 A table of contents listed in titles of the guidelines and an index is

provided to cross reference the guidelines to the affected regulations or

sections in chapter VI.

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MSC/Circ.488 - 2 -

TABLE OF CONTENTS

l Filled compartment, untrimmed

2 Dispensation from trimming filled compartments

3 Outdated reference

4 Deck edge immersion

5 Effect of longitudinal structure in filled or partly filled compartments

6 Securing holds loaded in combination

7 Volumetric heeling moments

8 Preparation of volumetric heeling moment curves

9 Permissible heeling moment table

10 Examples of calculations

11 Required stability information

12 Angle of flooding

13 Ballasting and deballasting

14 Boundary distance

15 Stowage factor

16 Length measured to a corrugated bulkhead

17 Assumed volumetric heeling moment of a filled compartment, untrimmed

18 Angle of grain shift in a filled compartment, untrimmed

19 Strength of grain divisions loaded on one side

20 Retaining saucers or bundles

21 'Tween-deck hatch covers

INDEX

I Regulation or Section Pertinent guideline I

2 1, 12

3 2

4 3, 4

5 5

8 6

11 7, 8, 9, 10, 11, 12 I Part B, Section I 14, 15 I Part B, Section II 5, 16, 17

Part B, Section IV 18

Part C, Section I 6, 19, 20, 21

Part C, Section II 6

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1

- 3 -

Filled compartment, untrimmed

(Reference: Regulation 2 - Definitions)

BACKGROUND

MSC/Circ.488

To facilitate interpretation of regulation 3(c) with regard to granting a

dispensation from trimming grain surfaces under certain conditions, the

following additional definition is appropriate in regulation 2.

GUIDELINE

A "filled compartment, untrimmed" is a compartment which is filled to the

maximum extent possible in way of the hatch opening but which has been granted

a dispensation from trimming outside the periphery of the hatch opening either

by the provisions of regulation VI/3(c) for all ships, or by MSC/Circ.323 on

the dispensation from trimming under-deck voids in filled cargo holds of

specially suitable ships. For other information applying to such

compartments, refer to guideline No.2.

2 Dispensation from trimming "filled" compartments

(Reference: Regulation 3 - Trimming of grain)

GUIDELINE

In addition to the provisions of regulation VI/3(c), dispensation from

trimming the under-deck spaces forward and aft of the hatchway on specially

suitable ships, as defined in part B, section V(B) of chapter VI, may be

granted in accordance with the provisions of MSC/Circ.323 which is appended to

these guidelines.

3 Outdated reference

(Reference: Regulation 4 - Intact stability requirements)

GUIDELINE

Due to the renumbering of certain regulations when the 1981 amendments to

SOLAS 74 were issued, the regulation cited in regulation 4(a) is incorrect.

Instead of regulation II-19 of SOLAS 60 and 74, the correct reference should

be regulation 11-1/22 of SOLAS 74, as amended. See, also, guideline No.11.

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MSC/Circ.488 - 4 -

4 Deck edge immersion

(Reference: Regulation 4(b)(i) - Intact stability requirements)

BACKGROUND

The stability requirements in regulation 4(b) are based upon statistical

evidence that a vessel which meets these standards will survive if

circumstances cause it to assume a permanent list of 12° in still water

recognizing that, at sea, the vessel will roll an additional amount to port

and starboard of this new axis. However, the statistical evidence was based

on a sample of ships which, when listed to 12°, did not immerse the deck

edge. Deck edge immersion has a strong relation to range of stability and

this factor is not, explicitly, included in the requirements set forth in

regulation 4(b). The footnote to regulation 4(b)(i) is a reminder of this

point. The following guideline is intended to emphasize that precaution.

GUIDELINE

To ensure an adequate range of stability after a shift of grain, it is

recommended that the permissible angle of heel be limited to the angle of deck

edge immersion if that is less than 12°.

5 Effect of longitudinal structure in "filled" or "'partly filled" compartments

(Reference: Regulation 5 - Longitudinal divisions and saucers Part B, section II - Assumed volumetric heeling moment of a

filled compartment)

BACKGROUND

When a grain shift occurs in a "filled'' compartment, structural members

such as longitudinal girders and hatch side girders impede the transverse

movement of the grain and, therefore, reduce the grain heeling moment

attributable to the transverse shift. Regulations 5(b)(i) and (b)(ii), and

part B, section II, address this effect, but experience indicates that these

rules have been interpreted in significantly different ways. It is evident

that there is confusion as to their intent. For example, is there a

difference in effect when one of these barriers is installed as part of the

structural support system of the ship as opposed to being provided for the

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express purpose of impeding the transverse movement of the grain? Or, whether

the member is ineffective if it is installed on a location other than the

centreline? A generally accepted interpretation, in effect authorized by

regulation 9, has developed over time and is set forth in the following

guideline.

GUIDELINE

5 .1 In "£ illed compartments" and in "filled compartments, untrimmed", all

graintight longitudinal members either permanent or temporary may be

considered as effective over their full depth for the purpose of limiting the

transverse shift of grain. If such a member is discontinuous longitudinally,

it should be considered effective over its actual length.

5.2 The division referred to in regulation 5(c) should be understood to mean

a temporary construction which is installed for the express purpose of

reducing the grain heeling moment by limiting the transverse shift of grain

and, as such, it should comply with the dimensional parameters described in

that regulation in order to be considered effectiveo With respect to

permanent longitudinal structures, such as girders, partial bulkheads, etc.,

whether on the centreline or not, these may be considered a9: effective for

their full depth for the purpose of preparing the volumetric heeling moment

curves for partly filled compartments.

6 Securing holds loaded in combination

(Reference: Regulation 8 - Combination arrangements Part C, section I (D) - Saucers Part C, section I (E) - Bundling of bulk Part C, section II(A) - Strapping or lashing

BACKGROUND

When holds are loaded in combination, void spaces exist beneath the deck

which are within the stow, as shown in figure 1 for a "filled" hold or figure

2 for a ''partly filled'' hold.

W/434ly/ETP

MSC/Circ.488 - 6 -

I I

,- ' ., I I I ffl.-(ed,, ' f

I

I 4 A QH ., ' '

I I i j I I

' '

Figure 1 Figure 2

In the case of figure 1, it is not permissible to reduce the grain heeling

moment by placing a saucer or a bundle within the coaming of the upper

hatchway. Similarly, in the case of figure 2, if the stability of the ship

cannot tolerate the grain heeling moment of the arrangement shown, it is not

permissible to eliminate the grain heeling moment by securing the upper

surface by means of strapping or lashing. The reason is that, in both

situations, the redistribution of some of the void spaces from beneath the

lower decks to the upper compartment (as described in part B, section II(C)),

has the potential for dropping the bundle or saucer from the confines of the

hatch coaming, or loosening the strapping arrangement and th,ereby diminishing

or defeating their effectiveness as a mechanism for reducing the grain heeling

moment.

GUIDELINE

It is recommended that compartments which are loaded in combination

should not utilize saucers, bundling of bulk, or securing by means of

strapping or lashing.

7 Volumetric heeling moments

(Reference: Regulation ll(a)(i) - Grain loading information)

BACKGROUND

Stability calculations deal with a heeling moment which is the product of

a weight times a distance. Therefore, regulation ll(a)(i) requires the grain

heeling moments be furnished as part of the grain loading information. This

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is cumbersome because each of several weights of grain would require a

separate grain heeling moment curve or tabulation for each cargo compartment.

To reduce the amount of data furnished, it has become the practice in most

grain loading booklets to provide curves or tables of volumetric heeling

moments in lieu of grain heeling moments. This reduces the size of the

booklet without loss of information because grain heeling moment is simply

volumetric heeling moment divided by the stowage factor of whatever specific

type of grain is being loaded. Therefore, to interpret regulation ll(a)(i) so

as to conform with general practice, the following guideline is given.

GUIDELINE

It is recommended that in the grain loading information furnished to the

master, heeling moment data for each cargo compartment be provided as

volumetric heeling moments rather than as actual grain heeling moments.

Instructions on how to accomplish the required conversion should also be

provided.

8 Preparation of volumetric heeling moment curves

(Reference: Regulation ll(a)(i) - Grain loading information)

BACKGROUND

The volumetric heeling moment for a cargo hold which is "filled" and

trimmed in accordance with regulation 3(a), is based on a grain shift of 15°.

It is to be especially noted that there is only one condition which is deemed

to be "filled". Any other condition, even one which is only minimally

different, is considered to be "partly filled", and the volumetric heeling

moment should be based upon a 25° grain shift. It is evident that the

volumetric heeling moment curves in some grain loading booklets do not

recognize this distinction. They show the uppermost point on the volumetric

heeling moment curve for the partly filled compartment to be coincident with

the volumetric heeling moment for the filled compartment. The following

guideline is intended to caution those involved in the preparation of grain

loading booklets, against making this error.

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MSC/Circ.488 - 8 -

GUIDELINE

The uppermost point on a curve of volumetric heeling moment versus either

depth of grain or ullage, in a partly filled compartment, should be based on

the void in the filled condition shifted 25°. In other words, the curve of

volumetric heeling moments for the partly filled condition should not be

terminated at the point, at zero ullage, which represents the volumetric

heeling moment based on a 15° shift as the moment applies only to the filled

condition.

9 Permissible heeling moment table

(Reference: Regulation ll(a)(ii) - Grain loading information)

BACKGROUND

Regulation ll(a)(ii) permits alternatives to the use of maximum

permissible heeling moments. However, experience now indicates that most

grain loading booklets contain curves or tables of maximum permissible heeling

moments. Thus, ships using alternative methods are a small minority and

suffer additional training problems due to use of non-standard methods and,

also, a lack of facilitation whenever compliance with the re~ulations is

verified by port authorities.

GUIDELINE

It is strongly recommended that grain stability information be presented

in the form of tables or curves of maximum permissible heeling moments versus

displacement and KG corrected for a liquid-free surface.

10 Examples of calculations

(Reference: Regulation ll(a)(iv) and (a)(v) - Grain loading information)

BACKGROUND

The intent of regulations ll(a)(iv) and (a)(v) is to illustrate the

correct use of the information furnished in the grain loading booklet by

providing meaningful, worked-out examples. This intention has not always been

fulfilled. Some grain loading booklets provide several examples which are

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essentially the same in that they merely demonstrate a single stowage

arrangement at various displacements. While it is not intended that the grain

loading booklet should include examples of every arrangement permitted by the

regulations, it should include both filled and partly filled holds. Also, if

data for "filled compartments, untrimmed" is furnished, examples of this

capability should be included.

GUIDELINE

The typical loading conditions required to be furnished in the grain

loading booklet should demonstrate the proper use of all the grain loading

information which is provided in the booklet.

11 Required stability information

(Reference: Regulation ll(b) - Grain loading information)

BACKGROUND

Regulation II-1/22 requires that stability information be furnished to

the master but it is non-specific. With respect to ships loading bulk grain,

regulation ll(b) provides a specific listing of stability information but it

is incomplete in that it does not include all the information needed to

perform the stability calculations required by this chapter. Accordingly, the

following guideline is provided to complete the list.

GUIDELINE

In addition to the stability information listed in regulation ll(b), the

following data should be provided:

(v) hydrostatic curves or tables; and

(vi) cross curves of stability calculated by either free trim or constant

trim method.

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MSC/Circ.488 - 10 -

12 Angle of flooding

(Reference: Regulation 11 - Grain loading information Regulation 2 - Definitions)

BACKGROUND

Experience now indicates that it has not been the usual practice to

identify the "angle of flooding" in the grain loading information furnished to

the master. Although this information is basic to the calculations which are

made to demonstrate compliance with regulation 4(b), it is not readily

obtained by direct observation of the types and arrangements of openings above

the weather deck on a ship. The following guideline is given to remedy this

omission.

GUIDELINE

The opening or openings into the ship accepted by the Administration as

establishing the "angle of flooding" should be identified in the grain loading

information furnished to the master. Such identification should include its

dimensional location with reference to the principal axes of the ship.

Alternatively, a table or curve of angle of flooding versus displacement may

be furnished.

13 Ballasting and deballasting

(Reference! None)

BACKGROUND

Sometimes, when the ballasting of a ship laden with bulk grain is

necessary in order to meet the stability requirements of this chapter, ballast

cannot be taken at the point of loading because of a water depth limitation or

the unsuitability of the harbour water. In such cases, the ship takes on

ballast after leaving the loading berth but before proceeding on the high

seas. The reverse situation also occurs with respect to deballasting upon

completion of a voyage. The regulations, neither in chapter VI nor in any

other part of the Convention, identify a point in the voyage at which full

compliance commences. The following guideline is intended to describe the

usual practice with respect to this question.

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GUIDELINE

When ballasting, necessary to meet the stability requirements of

chapter VI, cannot be accomplished at the loading berth any proposal to defer

ballasting should be approved by the port authority. However, at no time

during the ballasting operation should the GM corrected for a free liquid

surface, including the free surface in the ballast tank which is in the

process of being filled, be less than 0.3 m. Similarly, deballasting at the

end of a voyage should be subject to the same requirement.

14 Boundary distance

(Reference: Part B, section I(A) - Description of assumed voids and method of calculating intact stability)

BACKGROUND

Boundary distance, the dimension from the perimeter of the hatchway to

the boundary of the compartment, is used to calculate the average depth (Vd)

of the void in a "filled" compartment. Although it is a specific dimension

when measured perpendicularly to the periphery of the hatchway, it is not

explicitly defined as to how it should be measured in the corners of the

compartment. Refer to figure 3, which shows the forward end of a 'tween-deck

compartment in a general cargo ship.

(C) X (A) (C)

- - - ,-...L-----1- - - -

(B) . (B)

Figure 3

Dimension xis clearly the boundary distance in area (A). Dimension y is

the boundary distance in area (B). The question is - what is the boundary

distance in area (C), i.e. in the corners, and which girder depth (d) is to be

applied in the calculation of (Vd), the depth of the hatch end beam or the

hatch side girder. The following guideline addresses this question.

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MSC/Circ.488 - 12 -

GUIDELINE

When calculating the average void depth (Vd) in accordance with part B,

section I(A), the boundary distance in the corner of a compartment should be

the distance from the hatch end beam or from the hatch side girder to the

boundary of the compartment, whichever is the greater. The girder depth (d)

should be taken to be the depth of the hatch end beam or the depth of the

hatch side girder, whichever is the least.

15 Stowage factor

(Reference: Part B, section I(A)(c) - Description of assumed voids and method of calculating intact stability)

BACKGROUND

For the purposes of calculating the stability of a ship carrying bulk

grain, the regulations in part B, section I(A) (e) (1), defines "STOWAGE FACTOR''

as the volume per unit weight of grain cargo. This terminology is different

from usual merchant shipping practice whereby the stowage factor makes

allowance for "broken stowage", i.e. the fraction of the hold volume which

is not occupied by the cargo for various reasons such as interference of

structure, shape of cargo units, etc. This difference in meaning for a

commonly used shipping term has, from time to time, caused problems in the

grain trade with regard to its correct application. The grain heeling moment

is the product of a weight multiplied by a distance. The weight under

consideration is the weight of a solid mass of grain which shifts laterally

across the ship. The weight of this mass is not reduced by any lost volume

due to "broken stowage" within the mass. The following guideline is intended

to emphasize the stated intention of this regulation.

GUIDELINE

When calculating the grain heeling moment as the quotient of the

volumetric heeling moment divided by the stowage factor, stowage factor should

be taken to mean the volume per unit weight of the grain cargo as mandated by

part B, section I(A), and without any adjustment thereto. This value should

be calculated from the test weight of the grain as furnished by the loading

facility.

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- 13 - MSC/Circ.488

Length measured to a corrugated bulkhead

(Reference: Part B, section II(A)(a) - Assumed volumetric heeling moment of a filled compartment)

BACKGROUND

Since a corrugated bulkhead has more than one transverse, plane surface a

question arises as to where to measure length when a corrugated bulkhead is a

boundary of a compartment loaded with bulk grain. The following guideline is

intended to define the interpretation that, most generally, has been used.

GUIDELINE

When measuring length to a corrugated bulkhead, the length should be

deemed to be the distance to the midpoint between the outer and the inner

transverse, plane surfaces as shown in figure 4.

17

Figure 4

Assumed volumetric heeling moment of a filled compartment, untrimmed

(Reference: Part B, section II(A)(c) - Assumed volumetric heeling moment of a filled compartment)

BACKGROUND

In a "filled" compartment which is trimmed as required by

regulation VI/3(a), the above referenced section states that the resulting

graiil surface after shifting shall be assumed to be at an angle 15° to the

horizontal. It is implicit in this regulation that the void area above the

trimmed surface will be minimal as described by the average void depth (Vd)

assumption in part B, section I(A)(a). However, when the compartment is

W/434ly/ETP

MSC/Circ.488 - 14 -

filled but is exempted from trimming by regulation VI/3(c) because there is

additional filling, by means of feeding ducts or deck perforations, into the

void above grain surface at its natural angle of repose; there is no

implication as to the size of the remaining vo.id. It may be greater than or

less than the standard void. If it is greater, this raises the question as to

whether the 15° shift should still be applied. The regulations are silent on

this point. The following guideline pertains to this latter situation only.

GUIDELINE

Where dispensation from trimming of under-deck void spaces is granted in

accordance with the provisions of regulation 3(c), the angle of grain shift

should be assumed to be 25° to the horizontal. However, if any section of the

hold, i.e. forward abaft, or abreast of the hatchway, the mean, transverse

area of the void in that section is equal to or less than the void area which

would obtain if the section was trimmed as required by regulation 3(a), then

the angle of grain shift in that section may be assumed to be at 15° to the

horizontal.

18 Angle of grain shift in a filled compartment, untrimmed

(Reference: Part B, section IV(A) - Assumed volumetric heeling moments of a partly filled compartment)

BACKGROUND

The existence of an untrimmed grain surface within a filled compartment,

as permitted when a dispensation from trimming has been granted, raises a

question as to the angle of the surface after a _grain shift has occurred.

Part B, section I(A)(a)(ii), states that the untrimm~d surface before the

shift will be at an angle of 30°. Also, part B, section IV(A), states that,

after shift, the surface shall be assumed to be at an angle of 25°. But for

any part of the surface to change its angle from 30° before shifting to 25°

after shifting implies that the grain, in that part, has moved against

gravity, i.e. "uphill". The sketches below illustrate the question. Figure 5

is the alternative where part of the surface remains at 30° after shift and

the remainder is at 25° - there is no "uphill" movement of the grain.

Figure 6 is the alternative where the entire shifted surface is at 25°,

implying that some of the grain has moved "uphill". It is to be noted that

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the latter alternative is the assumption which is mandated by the

regulations. The following guideline is directed at emphasizing this intent

of the regulation.

Figure 5 Figure 6

GUIDELINE

When the free surface of the bulk grain has not been secured in

accordance with regulation 6 of this chapter, it should be assumed that the

grain surface after shifting will be at an angle of 25° to the horizontal

regardless of the initial angle of the surface of the grain ,before the grain

shift occurred.

19 Strength of grain divisions loaded on one side

(Reference: Part C, section I(C) - Grain fittings and securing)

GUIDELINE

It has been determined that there are deficiencies in the loadings given

in tables I and II of part C, section I(C), pertaining to the strength of

grain divisions loaded on one side. Therefore, when it is necessary to use

these tables, reference should be made to MSC/Circ.363, a copy of which is

appended to these guidelines. Also, it should be noted that the loads

specified in the tables in MSC/Circ.363 are expressed in Newtons per metre

length and not kN as marked.

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MSC/Circ.488 - 16 -

20 Retaining saucers or bundles

(Reference: Part C, section I(D) - Saucers Part C, section I(E) - Bundling of bulk)

BACKGROUND

The referenced regulations indicate that saucers or bundles shall be

placed within the coaming structure of the hatchway. However, casualty

experience indicates that there have been instances where the saucer or

bundle slipped beneath the retaining structure and thereby became largely

ineffective. The following guideline is intended to prevent this from

occurring.

GUIDELINE

In order to insure that a saucer or bundle is adequately anchored against

movement, stowage of the saucer/bundle tightly against adjacent structure

should be interpreted to mean having a bearing contact with such structure to

a depth equal to or greater than one half the depth specified for the depth to

the bottom of the saucer. If hull structure to provide such bearing surface

is not available, the saucer/bundle should be fixed in position by steel

wire rope, chain, or double steel strapping as specified by part C,

section II(A)(a)(iv), spaced not more than 2.4 m apart.

21 'Tween-deck hatch covers

(Reference: Part C, section I(F) - Securing hatch covers of filled compartments)

BACKGROUND

When bulk grain is stowed on several levels in the same cargo hold with

the openings between decks closed so as to form separate compartments, it is

possible for the grain to be transferred vertically from an upper level to a

lower level through openings in the joints of the 'tween-deck hatch covers.

This change of configuration of the void spaces can generate heeling moments

which were not provided for in the stability calculations.

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GUIDELINE

When bulk grain is loaded on top of closed, 'tween-deck hatch covers

which are not grain-tight, such covers shall be made grain-tight by taping the

joints, covering the entire hatchway with tarpaulins or separation cloths, or

other suitable means.

It is recommended that an instruction to this effect be included in the

grain loading booklets of ships to which this caution would apply.

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MSC/Circ.488 - 18 -

APPENDIX

STRENGTH OF GRAIN DIVISIONS LOADED ON ONE SIDE

1 The Maritime Safety Committee's attention was earlier drawn to

deficiencies in the loadings given in tables I and II of section 1 of part C

in chapter VI of the 1974 SOLAS Convention, and authorized the issue of

MSC/Circ.310 which circular indicated that tables I and II were only suitable

for divisions where the height of grain did not exceed 3 m and gave guidance

for grain heights in exce-ss of 3 m.

2 Subsequent discussion has indicated, however, that tables I and II may be

used for determining the load on grain divisions for grain heights of up to

6 m. The tables, in SI units, are attached.

3 For heights of grain in excess of 6 m, the tables of P/h2

, as given

herein, may be used as guidance in determining the load on a division.

Administrations should be guided by established engineering practice when

deriving the scantlings of high temporary divisions.

4 2

For clarification, an example of the use of the tables of P/h is given

hereunder:

To find Force (P) for a transverse division where h 1

L/h 2. From table II.L, P/h2 1846.

Force (P) 2

1846 X 9.0 149526 kN/m.

5 MSC/Circ.310 and Corr.1 is hereby revoked.

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- 19 - MSC/Circ.488

A. Longitudinal divisions

The load in kN per metre length of the divisions shall be taken to be as follows:

Table I

B (m) 1-=F,--! h(m) 2 3 4 5 6 7 I 9 10 I I

l. 50 6336 8626 9905 12013 14710 I 17 358 I 20202 2S939

2.00 13631 14759 16769 19466 22S06 I 25546 ;18r/33 35206 I I

2. 50 19466 21182 23830 26870 3030J I 33686 3726:, 44473

3 .00 25644 27900 30891 32323 I 38099 41874 ,'.15797 53748

3.50 31823 34568 37952 41727 I 45895 50014 54329 630C8

4.00 38148 41286 45013 Ll91BO I 53691 58202 62861 7227S

' 44173 47955 52073 ~1f,584 I 61488 66342 71392 81542 4. 50 I

5.00 ~0847 54623 59134 64037

I 69284 7,:i531 79924 90810

6.00 63498 68009 73256 78894 84877 90859 96968 109344 I

h height of grain in metres from bottom of the divisiµn.l/

B transverse extent of the bulk grain in metres.

a. For values of h equal or less than 6.00 m the force shall be determined by linear interpolation or extrapolation as necessary,

b. For values of h exceeding 6.00 m the force shall be determined using the values of p/h

2 given in table 1.1.

"!./ Where the distance from a division to a feeder or hatchway is 1 m or less, the height shall be taken to the level of the grain within that hatchway or feeder. In all other cases, the height shall be taken to the overhead deck in way of the division.

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-)

MSC/Gire. 488 - 20 -

B. Transverse divisions

The load in kN per metre length of the division shall be taken to be as

follows:

Table II

L ( ) m

I

I 2 3 4 5 6 7 8 10 12 14 h(m

1. 5

2.0

2.5

3.0

--

4.0

4.5

5.0

0

0

0

0

0

0

0

0

l~o 0 .

6570 6767 7159 7649 8189 8728 9169 9807 10199 10297

10199 10787 11474 12209 12994 13729 14416 15445 16083 16279

14318 15347 16426 17456 18437 19417 20349 21673 22408 22604

18878 20251 21624 22948 24222 25399 26429 27900 28684 28930

23781 25546 27164 28733 30155 31430 32558 34127 35010 35255

28930 I 30989 32901 34667 36187 37559 38736 40403 41286 41531

34274 36530 38638 40501 42120 43542 44767 46582 47562 47856

3:..1717 42218 44473 46434 48151 496221 50897 52809 53839 54182

50749 53593 56094 58301 60164 61782 63204 65263 66440 66832

h height of grain in metres from the bottom:of the divisions .. !./

L longitudinal extent of the bulk grain in metres.

a. For values of h equal or less than 6.00 ID the force shall be

determined by linear interpolation or extrapolation as necessary.

b. For values of h exceeding 6.00 ID the force shall be determined using

the values of p/h2

given in table 1.1.

!,/ Where the distance from a division to a feeder or hatchway is 1 m or less, the height shall be taken to the level of the grain within that hatchway or feeder. In all other cases, the height shall be taken to the overhead deck in. way of the division.

W/434ly/ETP

-16

·----10?97

J6279

??h04

28930

3=,2=:i:::i

4J5RO

47905

54231

66930

- 21 - MSC/Circ.488

Values of P /h'

Table I.1. Table II. l

B/h P/h' L/h P/h'

0.2 1687 0.2 1334

0.3 1742 0.3 1395

0.4 1809 0.4 1444

0.5 1889 0,5 1489

0.6 1976 0.6 1532

0.7 2064 0.7 1571

0,8 21 :,9 O.B 1606

1.0 235B 1.0 1671

1. 2 2556 1.2 172:,

~ • .a 2762 1.4 1759

1. 3 29b8 1.6 1803

1.8 3174 1.8 1829

2.0 3380 2.0 1846

2,2 3:,66 2.2 1B53

2.4 3792 2.4 J 857

2.6 3998 2." 1859

2.e 4204 2.8 18~9

3.0 4410 3.0 ll:l59

3,5 4925 ·3. ~ 1 H:>9

4.0 5440 4.0 18:,9

5.0 6469 5.0 18:,9

6.0 7499 6.0 1859

8.0 9569 8.0 1859

W/434ly/ETP